Managers and clinicians in the NHS are under growing pressure to improve and redesign services in a way that optimises health outcomes and controls costs. There is huge potential for health services research to make a larger contribution to this process but there is a disconnect between the theory and empirical evidence underpinning how best to design and deliver high quality health services, and what actually happens in practice. This has challenged policy makers, academics and front-line staff for decades. This 30 month multi-method study builds on previous knowledge mobilisation research funded by the HS&DR programme. It aims to increase the influence of health services research on decisions about the improvement and redesign of NHS services in two key ways. First, we will substantially develop the evidence base underpinning the nature and effectiveness of models of knowledge mobilisation specifically where researchers operate (or are ‘embedded’) within NHS service settings and evidence is created in partnership (or is ‘co-produced’) by researchers, practitioners and people who use services. Second, we will develop practical guidance on the design and implementation of co-production models for managers and clinicians in the NHS, its academic partners and people who use services. We propose four inter-linked work streams: work stream 1 comprises a critical narrative review of the literature in the fields of co-production and embedded research; work stream 2 comprises an environmental scan including a scoping review of up to 12 NHS embedded research initiatives; work stream 3 comprises four in-depth qualitative case studies of NHS embedded researchers and their associated networks, activities and impacts; and work stream 4 comprises a concurrent active engagement and influencing programme to ensure that the study achieves maximum impact in the NHS. Data collection and analysis will be informed throughout by methodological best practice, underpinned by the principles of co-production through engagement of stakeholders and supported by an international project advisory group.